A new blood test developed to predict TB

Seattle: An international team of researchers has identified biological markers in the blood that can help doctors predict who is at high risk of developing active tuberculosis (TB).

One-third of the world’s population is thought to be infected with Mycobacterium tuberculosis (Mtb), the bacterium that causes tuberculosis, but just a small fraction ever develops symptomatic illness.

If validated through additional clinical trials, a test based on these blood biomarkers that the researchers have now identified would allow doctors to target therapies to at-risk people, thus preventing them from getting sick.

The decade-long research effort was led by investigators from the South African Tuberculosis Vaccine Initiative at the University of Cape Town, and the Center for Infectious Disease Research, Seattle, US.

The findings were published in the journal The Lancet.

The biomarkers were identified in two stages. First, researchers collected blood samples for two years from more than 6,000 Mtb-infected but otherwise healthy adolescent volunteers in South Africa.

Analysis of the samples revealed patterns of gene expression that differed between volunteers who eventually developed TB and those who remained healthy.

This risk “signature,” confined to a set of 16 genes, could be detected in a blood sample as early as 18 months before the infected person developed active TB.

Next, the team confirmed the genetic risk signature’s predictive ability in a study of more than 4,500 volunteers in South Africa and The Gambia.

The second study group was more varied in age, health status, ethnicity and exposure to locally common strains of Mtb than volunteers in the first study.

Despite the differences, the same risk signature found in the first study was detected in the people who eventually developed active TB during the second trial. (IANS)

A relative adjusts the oxygen mask of a tuberculosis patient at a TB hospital on World Tuberculosis Day in Hyderabad, India. VOA

Tuberculosis (TB) is a vicious epidemic that is drastically underfunded. That was the takeaway message from the first high-level meeting focused on the infectious disease at the U.N. General Assembly in New York.

Amina Mohammad, U.N. deputy secretary-general, said the disease is fueled by poverty, inequality, migration and conflict, and that an additional $13 billion per year is needed to get the disease under control.

Last year, tuberculosis killed more people than any other communicable disease — more than 1.3 million men, women and children.

The World Health Organization estimates that the 10 million people who become newly infected each year live mostly in poor countries with limited access to health care.

The Bacteria that causes Tuberculosis

Dr. Tedros Adhanom Ghebreyesus, head of the WHO, told the assembly that partnership is vital to end the disease. He said the WHO is committed to working with every country, partner and community to get the job done.

The WHO plans to lead U.N. efforts to support governments and other partners in order to drive a faster response to TB.

Most people can be cured with a six-month treatment program. But as world leaders told the assembly, medication is expensive, and the stigma associated with TB interferes with getting people screened and treated.

Nandita Venkatesan, a young woman from India, told the assembly about the toll the disease has taken on her life. She got TB more than once, including a drug-resistant variety. She said it robbed her of eight years of her life while she was being treated. One of the medications she took to help cure TB robbed her of her hearing.

Just days before the high-level meeting, the WHO released its annual TB report. It found cases in all countries and among all age groups. It also found that two-thirds of the cases were in eight countries — India, Pakistan, Bangladesh, China, Indonesia, the Philippines, South Africa and Nigeria.

The meeting ended with the adoption of a declaration intended to strengthen action and investments for ending TB and saving millions of lives. (VOA)